feat(offline-session): implement logging UI onto session modal component

Added logging UI to the session modal:

Main Changes:

• Create a new session module in client/src/app/meditation
  • Reorganized start-meditation component into this module
  • Exports a session-btn component that opens a session-sheet modal
• Remove old "offline-meditation" logging component from profiles page
• Add new logging component log-component in session
  • Can pick a single date to log one session
  • Change pick a range of dates to log multiple sessions
• Edit POST /api/meditation endpoint to support multiple session dates